Transcript Mechanics of Breathing File

PULMONARY FUNCTION
AS Physical Education
Lesson Objectives
By the end of this lesson you will:
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Be able to describe the mechanics of breathing
Be able to identify the different lung volumes and
capacities
Epiglottis
Nasal Cavity
Pharynx
Larynx
Trachea
Bronchioles
Bronchi
Lung
Thoracic
cavity – the
space the
lungs are
within
Diaphragm
Roles Video…
https://www.youtube.com/watch?v=hc1YtXc_84A
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Approximately how many breaths do we take each
day?
What protects the nasal passageways? What do they
do?
What is the role of the epiglottis?
What do bronchioles end in?
Where does oxygen travel from the alveoli?
What does carbon dioxide do at the same time?
What happens when we exercise?
Structure…
Bronchi
Nasal Cavity
Hairs and mucous help to
filter the air
Epiglottis
Carry air to the lungs. Air is
warm, clear of most
impurities. Three bronchi right
/ two left
Rings of cartilage
Bronchioles
Small airways 1mm in
diameter containing
smooth muscle
Flap of cartilage at the
back of the tongue which
closes the top of the
trachea when you swallow
– prevents food going into
trachea
Trachea (windpipe)
Alveoli
12cm long by 2cm in diameter.
Rings of cartilage prevent it
from collapsing. Branches into
left and right bronchi
Minute air-filled sacs.
Approximately 300 million in
the lungs. Walls are thin and
surrounded by capillaries –
gaseous exchange via diffusion
Pharynx (throat)
Larynx (voice box)
Funnel shaped and
connects nasal cavity to
larynx. Muscular wall
composed of skeletal
muscle
Rigid walls of muscle and
cartilage. Connects pharynx to
the trachea, and extends about
5cm from third to sixth
vertebrae
Lungs
Located in the thoracic
cavity.
Right lung – 3 lobes
Left lung – 2 lobes
Mechanics of Breathing
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Inspiration – the process of breathing in. It is an
active process that involves the diaphragm and the
external intercostal muscles
Expiration – the process of breathing out. It is a
passive process that depends more on lung
elasticity than on muscle contraction
Inspiration
Expiration
Air into the lungs
Rest
1. Diaphragm contracts downwards
2. External intercostals contract (between
the ribs/outside of them) – pull the ribs
upwards and outwards – ribcage
3. Combined movements above mean that
thoracic cavity area increases – air
rushes in from outside environment (high
pressure) to lungs (now lower pressure
due to enlarged chest cavity)
Air out of the lungs
Rest
1. Passive process – does not need muscle
contraction
2. Diaphragm and external intercostal
muscles relax – rib cage falls back
inwards, recoils – thoracic volume
decreases – pressure increases – air
flows out of the lungs
3. Pressure inside chest higher than outside
of body
During exercise
1. Diaphragm and external intercostals
contract
2. Additional muscles help – pectoralis
minor (contracts to help top ribs move up
and out to assist increasing area) –
sternocleidomastoid/scalenes – neck
muscles (attach on top sets of ribs –
increase area)
3. Aim to make thoracic chest cavity
greater, larger volume of air in lungs
During exercise
1. Active process
2. Internal intercostals (inside of the ribs) –
contract and pull the ribs down and in –
thoracic volume smaller
3. Diaphragm relax and create a dome
shape
4. Abdominals – contract to aid
diaphragm relaxing – decrease chest
cavity quicker
5. Pressure builds inside thoracic cavity
and air rushes out
Video
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Watch the below animation
https://www.youtube.com/watch?v=NSEzg6TBheY
Internal and External Intercostals
Active
Process
Passive process at rest.
Active during exercise
Internal and External Intercostals
Internal (Expiration)
External (Inspiration)
Lie inside the ribcage
Lie outside the ribcage
Draw the ribs downwards and inwards,
decreasing the volume of the chest cavity
and forcing air out of the lungs during
expiration
Pull the ribs upwards and outwards,
increasing the volume of the chest cavity
and drawing air into the lungs during
inspiration
Diaphragm (separates the chest from the abdomen)
Abdominal
pressure decreases
(less than the air
pressure outside
the body)
so air is drawn
inwards
Abdominal pressure
increases (greater
than external air
pressure) so air is
forced out
During rest the diaphragm moves up and down approximately 2cm however during
exercise it can move 10cm +
https://www.youtube.com/watch?v=Mf8xTqfspp4
Lung Volumes and Capacities
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Process of inspiration and expiration causes
volumes of air to enter and leave the lungs
These volumes depend on the size, height, health
and gender of an individual
*The difference between a lung volume and a lung capacity is that a lung
capacity is made up of two or more volumes
Lung Volumes and Capacities
Label the provided diagram
Ventilation during exercise
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Rate (frequency) and depth (tidal volume) of breathing
increase in proportion to exercise intensity – why is this?
Meet the demand of the working muscles for O2 and to
remove CO2 and lactic acid
Tidal volume (TV) increases by utilising both IRV and ERV –
therefore both decrease during exercise
TV increases its usage of Vital Capacity (VC) from 10% at rest
to 60% during exercise – slight decrease
Minute Ventilation (VE) – increases dramatically – up to 20 or
30 times resting values
Lung Volumes
Lung
Volume/capacity
Average values at
rest (L)
Changes during
exercise
Tidal Volume
0.5
Increase
Inspiratory reserve
volume
Expiratory reserve
volume
Residual volume
3.1
Decrease
1.2
Slight decrease
1.2
no change
Vital Capacity
4.8
slight decrease
Minute Ventilation
6
Huge Increase
Total Lung Capacity
6
Slight decrease
Homework
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Using the worksheet provided, you are to compare
the changes in minute ventilation (VE) during submaximal and maximal exercise
Compare these at the different stages on the graph